In wireless full-duplex technology, signals may be received and transmitted on the same wireless channel at the same time. Spectral efficiency of the wireless full-duplex technology is the double of spectral efficiency of FDD (Frequency Division Duplex) technology or TDD (Time Division Duplex) technology. In an implementation of the wireless full-duplex technology, interference of a local-end transmission signal, which is received by a first transceiver from its own transmitting end, to an opposite-end transmission signal, which is received by the first transceiver from a second transceiver, needs to be eliminated as much as possible, such than the first transceiver may receives the opposite-end transmission signal from the second transceiver correctly. The opposite-end transmission signal is transmitted from the second transceiver to the first transceiver, which is a useful signal to be obtained. The local-end transmission signal is a signal transmitted from the transmitting end of the first transceiver. The received signal of the first transceiver includes a local-end transmission signal and an opposite-end transmission signal, both of which are received by the first transceiver. The first transceiver includes a first transmitter and a first receiver; and the second transceiver includes a second transmitter and a second receiver.
In the conventional technology, the self-interference may be eliminated as much as possible using technologies such as spatial interference suppression, analog interference cancellation and digital interference cancellation in the wireless full-duplex system, where the self-interference is interference of the local-end transmission signal received by the first transceiver to the opposite-end transmission signal in the received signal of the first transceiver. The analog interference cancellation technology mainly involves eliminating an interference signal of a received analog signal which is transmitted through a main path of the self-interference. The digital interference cancellation technology is a supplement to the analog interference cancellation technology. After the received analog signal of the first transceiver is converted to a received digital signal by an analog-to-digital converter, a self-interference signal may still be present in the received digital signal. The self-interference signal mainly includes a multi-path interference signal generated by reflecting the local-end transmission signal by surrounding objects. The digital interference cancellation technology involves eliminating residual self-interference signals in the received digital signal at the baseband to obtain correct and useful signals. Thus, a self-interference channel on which the self-interference signal is generated needs to be accurately estimated, so as to accurately obtain an estimation value of the self-interference channel to implement the digital interference cancellation.
In the conventional technology, in general, a first pilot signal is inserted into the local-end transmission signal transmitted from the first transceiver to the first transceiver, a second pilot signal is inserted into the opposite-end transmission signal transmitted from the second transceiver to the first transceiver. The first transceiver obtains a received first pilot signal and a received second pilot signal and performs a self-interference channel estimation based on the received first pilot signal and a known first pilot signal. The first transceiver performs a communication channel estimation based on the received second pilot signal and a known second pilot. In this way, variations of the self-interference channel and a communication channel are tracked, to obtain the correct opposite-end transmission signal. The first transceiver and the second transceiver transmit the pilot signals very frequently and significant communication resources are occupied, and thus the utilization rate of the communication resources is low.